Draft complaints spike in November. Almost every one of them comes down to three cheap parts.
The sweep is first. Hold a hand at the bottom of an exterior door on a windy day and you will usually feel exactly what is wrong. Sweeps flatten with age, and swapping one takes ten minutes.
Then the strike plate. If a door has to be hauled shut to latch, it is not sealing against the stop, and no amount of weatherstripping fixes that until the plate is moved a few millimetres.
Last is the stripping itself, which goes hard and stops springing back after a few winters. Replacing it around the frame, plus fresh exterior caulk where the frame meets brick or siding, is the best value job we do all season.
One exception. A window fogged between the panes has a failed seal and needs a new glazing unit, not a repair. We will say so straight away rather than sell you a fix that cannot work.